Controlled circulation boiler with novel dual furnace



y 1957 w. s. PATTERSON 2,797,667 CONTROLLED CIRCULATION BOILER WITHNOVEL DUAL FURNACE 4 Sheets-Sheet 1 Filed Dec 3. 1953 Fig. 1.

INVENTOR.

y 1957 w. s. PATTERSON 2,797,667

CONTROLLED CIRCULATION BOILER WITH NOVEL DUAL FURNACE Filed Dec 3, 19534 Sheets-Sheet 2 000000000 00 2826 Y Y W g E so. I

I I v INVENTOR. 1 Y 23 i Wardf P07 fer-.10,v flee U j 7 j fle/enTPaf/erJU/Z Emmi/X 7 BY Q. 8', A'I TO EY July 2, 1957 w. s. PATTERSON2,797,667

- CONTROLLED CIRCULATION BOILER WITH NOVEL DUAL FURNACE Fil ed Dec. s,1953 4 Sheets-Sheet a 4 Fig.4.

Fig. 5. BY @3673? y 1957 w. s. PATTERSON 2,797,667

CONTROLLED CIRCULATION BOILER WITH NOVEL DUAL FURNACE Filed Dec. 5, 19534 Sheets-Sheet 4 INVENTOR.

United States Patent Dfifice 2,797,667 Fatented July 2, 1957 CONTROLLEDCIRCULATION BOILER WITH NOVEL DUAL FURNACE Ward S. Patterson, deceased,late of Chappaqua, N. Y., by Helene T. Patterson, executrix, Chappaqua,N. Y., assignor to Combustion Engineering, Inc., New York, N. Y., acorporation of Delaware Application December 3, 1953, Serial No. 395,952

9 Claims. (Cl. 122-440) This invention relates to boilers of thecontrolled circulation type and particularly to such a boiler providedwith a dual furnace which includes a tubular division Wall.

In general the invention comprises a boiler having a steam generatingcircuit through which there is established a positive circulation bymeans of a suitable pump. The furnace of the boiler is divided into twoparallel compartments by means of a tubular division wall which forms apart of the steam generating circuit of the boiler. The tubes which makeup this wall are of serpentine configuration throughout a major portionof their length having tube portions laterally displaced from the medianplane of the wall first on one side thereof and then on the other sidethereof with certain of the tubes being displaced oppositely of othersthereby forming openings or passages through the wall. The tube portionswhich interconnect these laterally displaced tubes and extend throughthe median plane of the wall are in alignment across the wall atpredetermined elevations and at each of these elevations a pair ofstiffener tubes extend across the wall and are arranged so that theinterconnecting tube portions are embraced between the tubes of eachpair. These stiffener tubes are rigidly secured to the tubes of thedivision wall and form a part of the steam generating circuit of theboiler so that they are provided with a positive circulation. Thisdivision wall is very rigid being braced by the fluid cooled stiffenertubes and provides for pressure equalization in the two furnacecompartments through the numerous openings formed in the wall.

One of the general objects of this invention is to pro vide an improvedcontrolled circulation boiler of the type having a dual furnace providedwith a tubular division wall.

Other and further objects of the invention will become apparent to thoseskilled in the art as the description proceeds.

With the aforementioned objects in view, the invention comprises anarrangement, construction and combination of the elements of the boilerin such a manner as to attain the results desired as hereinafter moreparticularly set forth in the following detailed description of anillustrative embodiment, said embodiment being shown by the accompanyingdrawing wherein:

Figure l is a sectional view of a large capacity boiler embodying thepresent invention and showing the division wall extending throughout thelength of the furnace;

Figure 2 is a transverse sectional view of the furnace of this boilertaken generally along line 2-2 of Figure 1 and showing the dispositionof this division wall and the location of the burners for each of thefurnace compartments;

Figure 3 is a longitudinal sectional view of a portion of the divisionwall of Figure 1 taken along 33 of Figure l and showing in detail theconstruction of this wall;

Figure 4 is an enlarged detailed view of the wall portion of Figure 3taken generally from line 44 of Fig ure 3;

Figure 5 is a transverse sectional view of the division wall taken alongline 55 of Figure 4;

Figure 6 is a fragmentary detail view showing the method ofinterconnecting the wall tubes with the stiffener tubes;

Figure 7 is a side view of the detail of Figure 6 taken from line 77 ofFigure 6;

Figure 8 is a sectional view of a wall portion similar to that of Figure3 but showing a modified form of construction;

Figure 9 is a side view of the wall portion of Figure 8 taken from line9-9 of Figure 8;

Figure 10 is a transverse sectional view of the modified embodimenttaken from line 10-10 of Figure 9.

In many modern boiler installations wherein water walled furnaces areemployed the capacity of the boilers have become so large that it isnecessary to provide the furnaces of these boilers with a division walldividing the same into two compartments in order to maintain the ratioof protected area of wall surface of the furnace to the volume of thefurnace within the limits necessary for efficient operation. Since bothsides of such a division wall are exposed to the intense heat within thefurnace compartments the conventional means for stiffening the wall andsecuring the tubes together, including structural steel members securedto and extending transversely of the tubes, cannot be used because theywould quickly be destroyed by the intense heat generated within thefurnace. It is therefore necessary to provide a special means forstiffening these walls in order that they will be sufficiently rigid towithstand the rough usage to which they are subjected, Moreover, sinceno detrimental effect can occur because of the passage of combustiongases from one of the compartments of the dual furnace to the othercompartment through the division wall it is both permissible anddesirable to provide openings within this wall for the equalization ofpressure on both sides thereof thereby reducing or eliminating excessivestresses which would otherwise be produced in the wall because of adiiferential pressure existing thereacross.

The present invention contemplates a division wall for the dual furnaceof a controlled circulation boiler which is both structurally rigid andprovided with the openings necessary for rapid pressure equalization inthe two furnace compartments.

Referring now to the drawings wherein like reference characters are usedthroughout to designate like elements, the boiler of Figure 1 includesan elongated generally vertical furnace 10 of rectangular transversesection divided into furnace compartments 12 and 14 by verticallyextending tubular division wall 16 disposed between front and rear walls18 and 20. The upper portion of the furnace is in communication throughits rear wall 20 with horizontal gas pass 22 which extends substantiallythe full distance across said rear wall and which communicates with theupper end of gas pass 24. The fur naces bottom is of the hopper typeformed by inwardly sloping portions of front and rear walls 18 and 20terminating in spaced relation to form an opening for passage of ashinto pit 25.

Each'of the furnace compartments is provided with burners 26 locatedadjacent the corners of the compartments for the purpose of tangentialfiring in a well known manner.

The steam generating circuit of the boiler includes tubes 28 which linethe four walls of the furnace and extend throughout the length of thesewalls and tubes 30 which extend throughout the length of the furnace andmake up division wall 16. All of these tubes are connected attheir-upper or outlet'ends with steam and water drum 32 through suitableheaders and connecting conduits and at their lower or inlet ends withpumps 36 (only one being shown) likewise through suitable headers andconnecting conduits. The pumps 36 receive boiler water from drum 32through downcomers 34 and are eifective to force this boiler waterupwardly through tubes 38 and 40back into drum 32 with a portion of thewater being 'co'nvertedto steam during its passage through these tubes.The inlet or lower ends of division wall tubes 30 are bent toward thefront and rear walls of the furnace as shown in Fig. 1 so thatapproximately half of these tubes project throughthe sloping portion ofthe front wall at right angle thereto while the remaining tubes'projectthrough the sloping portion of the rear walls at right angles theretowith the tube ends connecting into inlet headers 35 positioned adjacentand in parallel relation with these sloping wall portions.

In controlled circulation boilers a flow restrictor or orifice isprovided for each of the tubes, preferably at the inlet of the tube, inorder that the flow through each tube may be regulated as desired formaximum operatingefficiency of the unit. Thus in the boiler of Fig. 1,although not shown, each of the tubes 28 and 30 is provided with anorifice to regulate flow through the tube.

The steam generated in the steam generating circuit passes from steamand water drum 32 through superheater sections 36 and 38 in the usualmanner and then to a desired point of use such as a turbine. In additionto having superheater section 38 disposed therein gas pass 22accommodates reheater 40 to which steam, after having a portion of itsenergy utilized, is returned for reheating to a desired temperature andpressure.

In order to provide division wall 16 with openings throughout at least amajor portion of its length for the purpose of equalizing pressuredifferentials in furnace compartments 12 and 14, which are caused bypuffs, unequal dis'tributionof fuel and the like, tubes 30 of this wallare bent in a serpentine manner whereby portions of each tube aredisposed first on one side of the median plane and then on the otherside of this median plane as clearly shown in Fig. 3. Adjacent tubes areoppositely bent thereby forming passageways 42 therebetween which areeffective to equalize the pressurein the two furnace compartments.

The portion of tubes 30 which extend through the median plane of Wall'16 and interconnect the laterally displaced tube portions are disposedin alignment across thewall, as shown in Figs. 3, 4, 8 and 9, and at thelocation of these aligned tube portions a pair of fluid cooled stiffenertubes extend across the wall with these aligned tube portions positionedintermediate the pair of stiffener tubesand rigidly connected thereto.

In the embodiment of Figs. 1 through 5, these pairs of stiffener tubes,identified as 44, are in the form of a U with the two legs thereof(which constitute the pair of tubes) positioned one above the other andembracing the aforementioned aligned tube portions therebetween. Theends of the U-shaped tubes 44 are serially interconnected with thefurnace wall tube 28 which is adjacent thereto and disposed in the planeof the division Wall (Figs. 4 and 5) so that boiler water which isforced through this tube 28 flows through stiffener tubes 44. TheU-shaped stiffener tubes 44 are oppositely arranged throughout thelength of wall 16 so that they are alternately interconnected with andform a part of the tube 28 at one-edge of the wall and the tube 28 atthe other edge of the wall.

In order to assist in preventing division wall 16 from moving eitherlaterally or vertically within furnace 10 the return bends of stiffenertubes 44 are positioned in between a pair of wall tubes 28 with the walltube which lies in the median plane of division wall 16 being bentoutwardly to permit this positioning of the return bend. Since theoutward bend of this tube 28 closely conforms with the return bend thisarrangement prevents the stiffener tube 44- from moving both verticallyand laterally within the furnace.

The stiffener tubes 44 are rigidly secured to each of the division walltubes 30 and for this purpose metal connector plates 46 may be provided,these plates being welded to the stiffener tubes 44 and the divisionwall tubes 38 as shown in Figs. 6'and 7.

The division wall thus provided is extremely rugged because of stiffenertubes 44 extending thereacross at predetermined intervals and sincepassageways 42 are provided across the the entire wall as well asthroughout its length any pressure differential between furnacecompartments 12 and 14 will be quickly equalized preventing theformation of undue stresses in the wall.

In addition to providing an extremely compact tube and headerarrangement the disposition of the lower ends of tubes 30 and theirinterconnections with headers 35 forms a large centrally located passage48 (Fig. l) which establishes communication between furnace compartments12 and 14 and is effective to assist in the equalization of pressure inthe two compartments.

While stiffener tubes 44 have been disclosed as interconnected with thewall tubes 28 of the furnace in a highly efficient manner so that boilerwater is forced through tubes 44 this represents only one possiblearrangement for fluid cooling the stiffener tubes since any arrangementwhich establishes a forced circulation through tubes 44 will beefiective, although perhaps not as compact or efficient as theorganization shown.

The modified embodiment of Figs. 8, 9 and 10 differs from the embodimentof Figs. 1 through 7 by having the tubes making up each pair ofstiffener tubes 44, i. e., the two legs of the U-shaped tube, disposedin a horizontal rather than a vertical plane with the return bend whichinterconnects the tubes in each pair embracing the adjacent wall tube 28which lies in the median plane of division wall 16 (Fig. 10). The walltubes 28 on both sides of the wall tube embraced by the return bend arebent outwardly to permit the return bend to embrace the tube asaforesaid and by this arrangement the pair of stiffener tubes 44' areprevented from moving laterally or vertically within the furnace.

The tube'portions embraced by each pair of stiffener tubes 44' are soinclined with respect to the median plane of the wall as to permit thetubes 44 to be positioned Within the'extremities of the division wallssurfaces thereby providing greater protection for the stiffener tubesagainst the deleterious effects of the intense heat within the furnacethan if these tubes projected laterally from the surfaces of thedivision wall.

As in the case of the previously described embodiment the ends ofU-shaped stiffener tubes 44 are serially interconnected with the furnacewall tube 28 which is adjacent thereto and disposed in the plane of thedivision wall with the stiffener tubes being oppositely arrangedthroughout the length of division wall 16 so that they are alternatelyinterconnected with and form a part of the tube 28 at one edge of thisWall and tube 28 at the other edge of this wall.

While I have illustrated and described a preferred embodiment of mynovel boiler organization it is to be understood that such is merelyillustrative and not restrictive and that variations and modificationsmay be made therein without departing from the spirit and scope of theinvention. I therefore do not wish to be limited to the precise detailsset forth but desire to avail myself of such changes as fall within thepurview of my invention.

What is claimed is:

l. A boiler of the controlled circulation type having a steam generatingcircuit and a pump means effective to force the boiler watertherethrough, a tubular division wall separating the furnace of theboiler into two compartments each of which communicates with a gas passleading from the furnace, said tubes being vertically arranged inadjacent side by side relation with certain adjacent tubes beinglaterally offset relative to one another throughout at least a portionof the walls length so as to provide openings in said Wall forcommunication between the compartments through the division wall withother portions of the tubes being in alignment across the wall at spacedpredetermined intervals, generally horizontal stiffener tubes extendinglaterally across said division wall at said predetermined intervalsthroughout the length of said wall and secured to the tubes thereof,said stiffener tubes forming a portion of the steam generating circuitof the boiler.

2. In a boiler of the type described wherein pump means force boilerwater through the steam generating circuit, an upright elongated furnacedivided into two parallel compartments by a tubular division wall whichforms a part of said steam generating circuit and has the tubesextending longitudinally thereof in adjacent side by side relation withcertain adjacent tubes of said wall being laterally offset relative toone another throughout at least a portion of the walls length to formopenings in said wall with other portions of the tubes being inalignment across the wall at spaced predetermined intervals, a pair ofstiffener tubes extending across the. wall at at least some of saidspaced predetermined intervals with the tubes of the wall disposedbetween said pair of stiffener tubes and rigidly secured thereto, saidstiffener tubes being connected into and forming a part of the boilerssteam generating circuit.

3. In a controlled circulation boiler having an upright furnace theinner surface of the walls of which are lined with vertically extendingsteam generating tubes forming a portion of the steam generating circuitof the boiler, a vertically disposed tubular division wall extendingacross the furnace and dividing the same into two sections with thetubes of said wall disposed generally vertical and a portion of each ofthese tubes being laterally displaced from the median plane of the wallfirst on one side thereof and then on the other side thereof withcertain of said tubes being displaced oppositely of others and with theI tube portions that extend through the median plane and interconnectthe tube portions disposed on each side of the median plane being inalignment across the wall, U- shaped alignment tubes extending acrossthe wall at the locations of the said interconnecting tube portions thatpass through the median plane, said alignment tubes having the divisionwall tubes interposed between and interconnected with the legs thereof,the boiler walls inner surface having pockets formed therein to snuglyreceive the return bends of the alignment tubes and prevent displacementof the same, said alignment tubes forming a portion of the steamgenerating circuit of the boiler and having boiler water forcedtherethrough.

4. A controlled circulation boiler having an upright elongated furnacethe inner surface of the Walls of which are lined with verticallyextending steam generating tubes forming a portion of the steamgenerating circuit of the boiler, a vertically disposed tubular divisionwall extending across the furnace and dividing the same into twosections with the tubes of said wall disposed generally vertical and atleast a major portion of the length of said tubes being of serpentineconfiguration weaving through the median plane of the wall so that eachtube is displaced from said median plane first on one side thereof andthen on the other side thereof with certain tubes being displacedoppositely of others and with the tube portions that extend through saidmedian plane being in alignment across the wall at predeterminedelevations therealong, U-shaped alignment tubes extending across thewall at the locations of said aligned tube portions that penetrate themedian plane of the wall and embracing said tube portions between thelegs thereof, said tube portions and said alignment tubes being rigidlysecured together, the legs of said U-shaped alignment tubes beingserially interconnected with the furnace wall tube juxtaposed to theedge of the division wall adjacent the ends of said legs and the boilerwalls inner surface having pockets formed therein snugly receiving thereturn bends of said alignment tubes to prevent displacement thereof.

5. A controlled circulation-boiler having an upright elongated furnacethe inner surface of the walls of which are lined with verticallyextending steam generating tubes forming a portion of the steamgenerating circuit of the boiler, a vertically disposed tubular divisionwall extending across the furnace and dividing the same into twosections with the tubes of said wall disposed generally vertically andat least a substantial portion of the length of numerous of said tubesbeing of serpentine configuration weaving through the median plane ofthe Wall so that each such tube is displaced from said median planefirst on one side thereof and then on the other side thereof withcertain tubes being displaced oppositely of others and with the tubeportions that extend through said median plane being in alignment acrossthe wall at predetermined elevations therealong, U-shaped alignmenttubes extending across the wall at the locations of said aligned tubeportions that penetrate the median plane of the wall and snuglyembracing said tube portions between the legs thereof, and the legs ofsaid U-shaped alignment tubes being serially interconnected with thefurnace wall tube juxtaposed to the edge of the division wall adjacentthe ends of said legs.

6. The organization of claim 5 wherein the legs of the U-shapedalignment tubes are one above the other.

7. The organization of claim 6 wherein the legs of the U-shapedalignment tubes are side by side.

8. A controlled circulation boiler having an upright elongated furnacethe inner surface of the walls of which are lined with verticallyextending steam generating tubes forming a portion of the steamgenerating circuit of the boiler, a vertically disposed tubular divisionwall extending across the furnace and dividing the same into twosections with the tubes of said wall disposed generally vertically andat least a substantial portion of the length of said tubes being ofserpentine configuration weaving through the median plane of the wall sothat each tube is displaced from said median plane first on one sidethereof and then on the other side thereof with adjacent tubes beingoppositely displaced and with the tube portions that extend through saidmedian plane being in alignment across the wall at predeterminedelevations therealong, U-shaped alignment tubes extending across thewall at the locations of said aligned tube portions that penetrate themedian plane of the wall and snugly embracing said tube portions betweenthe legs thereof, and the legs of said U-shaped alignment tubes beingserially interconnected with the furnace Wall tube juxtaposed to theedge of the division wall adjacent the ends of said legs.

9. In a boiler of the type wherein the fluid is forced therethrough by apump the combination of an elongated furnace the inner surface of thewalls of which are lined with side-by-side tubes, a division wall insaid furnace extending longitudinally thereof and made up oflongitudinally disposed tubes positioned in side-by-side relation,numerous of said tubes being of serpentine configuration having portionsthereof displaced from the median plane of the wall with certain tubesbeing displaced oppositely of others, these tubes also having portionspositioned in said median plane and which are in alignment across .thewall at several longitudinal positions herealong, said division Wall atthe location o'fpsaid aligned tube portions having tubes extendinglaterally thereacrcss and embracing and connected to the longitudinal.tubes of said Wall, these laterally extending tubes being in series withand forming part of-tubes lining the inner surface of the furnace Wallat the edges of the division wall.

References'Cited 'in the file of this patent 7 UNITED STATES PATENTS

